Secure proximity verification of a node on a network

A node on a network including:

• A processor configured to prepare a first response at the node prior to receiving any part of a query from a source node;
• and
• a communication device configured to:
• receive the query from the source node,
• transmit the first response from the node to the source node, immediately after the query is received and before the processor processes the query, and
• transmit a second response from the node to the source node,
• wherein the processor is further configured to process the query and to produce therefrom the second response that facilitates a verification of the node, to the source node,
• wherein the source node determines the proximity of the node based on a measure of communication time, by comparing the measure of communication time with a threshold value, and if the communication time is below the threshold value, the node is determined to be local, otherwise the node is determined to be remote,
• and wherein the source node uses the remote/local proximity determination to control subsequent communications with the node based on the determined proximity,
• and wherein the communication device is further configured to:
• receive selected files from the source node only when the node is determined to be local.

A node on a network including:

• a communication device configured to transmit a query to a target node and to receive a first response and a second response from the target node;
• and
• a processor configured to:
• measure a communication time between transmitting the query and receiving the first response,
• determine a proximity of the target node relative to the node based on the measured communication time, said proximity determination including comparing the measured communication time with a threshold value, and if the measured communication time is below the threshold value, the target node is determined to be local, otherwise the target node is determined to be remote and
• verify the target node based on the second response
• wherein the node uses the proximity determination to control subsequent communications with the target node based on the determined proximity, in that selected files are permitted to be transferred from the source node to the target node only when the target node is determined to be local.